Given, inductance of coil, L = 2H
Reactance of coil, when it is connected to AC source,
${\left(X_L\right)}_{AC}=\frac{1}{\omega L}$ where, $\omega =$ angular frequency
${\left(X_L\right)}_{\omega }=\frac{1}{2\mu \omega }$
For DC source, inductor coil behaves pure conductor, hence ${\left(X_L\right)}_{DC}=0$
$\therefore \frac{{\left(X_L\right)}_{AC}}{{\left(X_L\right)}_{DC}}=\frac{2\omega }{0}=\infty$ (at infinity)